Insect Moulting Hormones: Possible Intermediates in the Metabolism of Cholesterol to Ecdysteroids in an Insect

Abstract

The possible ecdysteroid precursors 3β,5,14x-trihydroxy-5α-cholest-7- en-6-one (12) and 3β,14α-dihydroxycholesta-4,7-dien-6-one (19) have been synthesized and the metabolism of the corresponding 3α-tritium- labelled compounds studied in Calliphora stygia at the time of ecdysteroid biosynthesis. Labelled 20-hydroxyecdysone was isolated in both cases and the compounds may thus be ecdysteroid precursors. However, confirmation of these results with substrates labelled in another position is necessary.